City Research Online

Abstract

The aeroacoustics of a tripped NACA0012 aerofoil with an array of self-oscillating flexible flaplets attached to the trailing edge at low to moderate Reynolds number and at geometric angles of attack ag = 0? - 20? is investigated. A low frequency noise reduction occurs at a chord based Strouhal number of 2 - 3 across all Reynolds number and angles of attack. With maximum reductions reaching up to 8 dB within the Strouhal number range. This reduction is proposed to be due to a modification of the instabilities in the shear layer by the self-oscillating flaplets. A slight increase in noise level is seen at higher frequencies, however once the overall sound pressure level is calculated there is still a net overall reduction.

Publication Type:	Book Section
Additional Information:	© 2019 Proceedings of the International Congress on Acoustics. All rights reserved. 23rd International Congress on Acoustics, ICA 2019, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019; 4th EAA Euroregio, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019, Berlin, Germany : Deutsche Gesellschaft für Akustik.
Publisher Keywords:	Passive oscillators, aeroacoustics, trailing edge flaplets, fluid structure interaction
Subjects:	T Technology > TJ Mechanical engineering and machinery T Technology > TL Motor vehicles. Aeronautics. Astronautics
Departments:	School of Science & Technology > Engineering
Related URLs:	https://pub.dega-akustik.de/ICA2019/data...

Export

Downloads